Incest

In all states marriage between a parent and child is prohibited as well as all marriages between biological brothers and sisters and between grandparents and grandchildren. These laws are well settled and uniform. The laws which vary by state are those between first cousins, uncle and niece or aunt and nephew as well as relationships between adopted children.

Uncle-niece and Aunt-nephew

Several states prohibit marriages between an uncle and niece or an aunt and nephew, including California, Colorado, Illinois, Montana, New Hampshire, New York and Pennsylvania.

Other states, including Arizona, Illinois, Indiana, Main, Utah and Wisconsin, only outlaw first cousin marriages under certain circumstances. For example Wisconsin will allow a first cousin marriage once a woman is 55 years old. The rational for this is that a woman over the age of 55 is less likely to conceive a child. Wisconsin will allow first cousin marriage even if the woman is under the age of 55 if it is provided that the couple is unable to conceive a child. First cousin marriage is legal in all other states.

Recent research has found that the risk of first cousin marriage leading to children with birth defects may be much lower than is commonly believed. Studies done in 2002 and 2009 show that the risk of first cousin offspring having birth defects is no greater than that of a woman over 40 becoming pregnant (as compared to a 30 year old woman conceiving a child with her first cousin). This data has struck a cord with many considering that the number of births to mothers over 40 has almost tripled in the past two decades. The National Conference of Commissioners on Uniform State Laws (NCCUSL) has recommended that all states repeal their prohibitions on first cousin marriages, however, no states that outlaw it have done so.

Adopted Children

In most states the laws regarding marriage between stepchildren and adopted children are unclear. Two states, including Mississippi and Texas passed laws against such marriages. However, in Texas a 1978 case held that the law failed the “test of minimum rationality” and held it violated the Fourteenth Amendment to the US Constitution. In contrast, almost every state has laws that would clearly make any marriage between an adopted child and the parent incestuous and illegal.

Conflicts of Laws

Realizing the laws of the various states vary, one may ask: What happens when a couple marries in a state, where their relations are permitted, and then move to a state where they are not? The answer, unfortunately, is that it varies greatly from state to state in both law and rational.

The best answer that can be offered here comes from Second Restatement of Conflicts of laws, which is widely adopted. It states that a marriage that is valid in the state where the spouses married should be honored by other states unless it violates a strong public policy of another state that has a more significant relationship to the spouses and the marriage. A clearer answer may require research specific to the issue, the states involved and the circumstances of a particular married couple.

If a marriage is incestuous most states will consider it “void.” Meaning that the marriage is automatically void if it is incestuous. As a practical matter this may need to be demonstrated in Court to establish that the marriage is in fact void. This means that upon acceptance of evidence and a finding that the marriage is incestuous most states will treat the marriage as if it never happened.

For example, his would mean that the wife would automatically retake her maiden name because, since the marriage is treated as if it never existed, she technically never really had the right to take the married name in the first place.

Another example is where an incestuous married couple lives together as husband and wife and then the husband is killed in an accident at work. If it is then discovered that the marriage was incestuous, the wife will receive no workman’s compensation because the state will treat her as if they were never married, because the marriage is “void.”

Other examples involve the difficult issues of what happens to the marital estate if the marriage is voided. Principals of equity can assist a court in dividing the couples assets but generally there is no basis for alimony because, again, the court will treat the couple as if they were never married in the first place. Therefore, there is no divorce and no right to alimony.

Child support is a different matter however. Because child support is given on the basis of the state’s interest in looking after the child, there is no requirement that a couple be married in order to award child support. Thus, even if a marriage is voided, child support would still be required by the Court.

A few states hold that incestuous marriages are merely voidable. The significance of this is that the state will continue to recognize that the couple was in fact married for some period of time. These states include: Maryland, Ohio, South Carolina, Virginia.